521 firing problem

[Beginer]

I have a 70 521 with the L16 and has single points system. I drove it roughly 300 miles after changing the plugs, points, and coil, when it just died on me while i was going 60 like i turned off the key. At first it would start up for and run very rough like it was out of time. Now i can't get it to run at all since trying to adjust the timing.

The coil still works when i hook a spark plug to it, i just can't seem to get the plugs to fire normally. I also looked over the cap and rotor and they appear to be fine.

 

I'm normally a decent mechanic so assume its something simple i am forgetting to check, or can the cap and or rotor spontaneously fail?

 

Any help, ideas are much appreciated.

[ggzilla]

Most commonly the points. Check the dwell, its probably off.

 

Also the coil may be bad. New ones are junk compared to the original ones.

 

Bad cap & rotor is unlikely but visually inspect them just in case.

[Beginer]

I rechecked the cap and rotor, they look fine.

I checked the dwell on the points best i can, I fold a corner of a piece of papper to get a 45 degree, it was just slightly more like the book says. (49-55 degrees)

 

One thing i noticed but didn,t think of is the rotor does not line straight up with the plug terminal, the edges are close-ish as far as i can tell. I am not 100% but i believe my truck came with dual points, if someone had changed the distributor before i got it could it be misaligned?

[ggzilla]

That's no problem.

 

But 45 degrees dwell is too little. Minimum is 49 degrees .

[Beginer]

Could the point lobe thing(whatever its called) have really worn enough to mess up the dwell in 300 miles?

[ggzilla]

Something has gone out of spec in 300 miles, hasn't it?

[wayno]

Turn the crank to TDC and pull the valve cover off, are the cam lobes on number 1 cylinder pointed at 10am and 2pm?

Is the rotor pointed to number one spark plug wire post?

[dat521gatherer]

The truck dying doing 60 is going to be your biggest clue. Generally this will not be a tune problem. You can drive with points not opening and it will back fire. You can drive with a fouled plug and still drive it. Original coils almost never go out, maybe your old one is still around?

 

I had one of the arms of my points burn completely off going down the freeway once. I see this is not your problem.

 

My blue 521 sometimes dies going down the freeway but starts right back up so I can't trouble shoot it. I think I loose all power when it happens as my dummy lights dont come on when it happens but come back on before I can get out of the truck most of the time. Again I see this is not your problem.

 

Check plug number 4 and 3 for fouling. I had a engine that would foul new plugs after a couple hundred miles. Ended up getting a anti plug fouler for cylinder #4.

 

If it was running I'd say put  a timing light on it to see if all 4 are firing but you have to get it started first to do that.

[banzai510(hainz)]

why you change the coil?

You put a point coil back in there? made a for a 521 datsun?

 

If it ran till 60 then stoped sound like the rotor position is not the proplem cause it went to 60mph. TGis will not change unless the bolt fell out and the whole distributor turned.

 

 

maybe a valve lash fell out.

if you get spark then I assume your fine at least in the biggining.

 

You sure you didndt run out of gas.

Ck out put of the fuel pump

ck the carb see if gas squirts in there when cycling the linkage

ballast resisitor OK

 

Pertronix make a single point conversion to get rid of the points. 85$

 

 

dont be lazy watch this and read olddatsuns.com the tech section and theres You tube of the valave adjustment

[datzenmike]

NEVER throw old parts away. Until sure the new ones are working and can be trusted. Never fix something that is working. Put you coil and rotor back on, it's fine. If you replaced with electronic ignition coil the points have burned up.

[Beginer]

I put a new set of points in and gapped them at .020" possiblly a little less. I am getting consistent fire out of the coil to ground, but i am only getting occasional firing signal when hooked up properly 

 

(timing light hooked to the coil wire)

 

cam lobes at 10 & 2

 

seems close enough to me

 

 

 

 

I am going to check the valve lash and will report back

 

[ggzilla]

Lash has zero to do with getting spark from coil to plugs. Neither does the cam timing.

 

If the coil sparks, but the spark plugs dont, something is wrong between the coil and plugs. This means the spark plug wires or distributor.

 

Possible causes:

* burnt out wire

* carbon tracking in cap

* rotor grounding out to shaft

* drive tang busted on distributor

 

Test it, don't guess.

 

Take the cap off and watch while cranking the engine. If the rotor doesn't turn, you found the problem.

T

[Beginer]

I tested the ohms on the wires through the cap just to make sure they were getting a good connection, tested fine.

 

Cleaned inside of cap, was not dirty or anything just a little dust.

 

If the rotor was grounding out to the distributor shaft the timing light I have hooked up to the coil wire would light up every time, which it does not.

 

And the rotor does go round and round when i turn over the engine.

 

 

I know valve lash has nothing to do with my firing problem but could be part of the reason it died initially, and most of them are out of spec so I am going to fix that and it may start easier if those are appropriate.    

cyl 1 intake .007 exhaust .010

cyl 2 intake .004 exhaust .008

cyl 3 intake .014 exhaust .008

cyl 4 intake .004 exhaust .011

[Beginer]

Is it physically possible to put the points plate from a single point distributor in a dual points housing?

 

the reason i ask is the location of the rotor on the shaft looks like the dual points one here: http://www.oreillyauto.com/site/c/detail/A1C0/31602/02780.oap?year=1969&make=Nissan&model=521%2BPickup&vi=1495529&ck=Search_distributor_1495529_2580&keyword=distributor

 

not like the single point they have a picture of http://www.oreillyauto.com/site/c/detail/A1C0/31601/02780.oap?year=1970&make=Nissan&model=521%2BPickup&vi=1212310&ck=Search_distributor_1212310_2580&keyword=distributorh_distributor_1212310_2580&keyword=distributor

 

the numbers on the side of mine are   d412-59     004a

 

when i googled it I got dual point ditributors, but i just want to see if some one here has run across something like that before.

[wayno]

If it ran before for 300 miles, that is not the issue. ^^^

When the cap is off, turn the ign. on and make sure you have spark at the points by opening and closing the points with a screwdriver, and I am assuming that they are closed when doing this test, I always check this when starting an engine that has been sitting for a long period of time.

 

 

OK, I am the one that suggested checking the cam timing David, I figured it quit while driving down the road, what if one of the timing chain gears got ate up and the chain skipped some teeth, but it looks good, so that is not the issue.

Recently I had some issues because of old spark plug wires, I finally figured it out when I used a remote start button at night, I could see the coil wire arcing to a ground, it was actually the dust cap that was the issue, that dust cap was likely 30+ years old.

If an EI coil was used with points, that likely could cause issues.

 

How does one check a condenser?

[Beginer]

The wires on the truck have been on there for less than 2k miles, 3 or 4 years. But i will see if they arc tomorrow just to make sure.  I have a function on my multimeter to test a condenser i just need to find my manual, and i will do that also. 

the main reason i asked about the point plate swapping is my timing adjustment was pushed to or close to its limit in one direction and when i do get it to fire, it back fires. but tries to spin the wrong way.

the spark to the plugs seems rather hit and miss, according to my timing light at least.

 

is there an ohm reading difference between an EI coil and a points one?      

Because the coil i have in it right now reads 1.5 ohms primary (3.1 ohms if you include the resistor), and 5k or 7k on the secondary

[ggzilla]

is there an ohm reading difference between an EI coil and a points one?

Because the coil i have in it right now reads 1.5 ohms primary (3.1 ohms if you include the resistor), and 5k or 7k on the secondary

Yes. Datsun points coil is 1.5 ohms + 1.5 ohm resistor. Datsun high energy EI coils are 0.7 ohms

[banzai510(hainz)]

Dude.

If this ran for 300miles fine then the distributor timming and cam timming is fine. Just dial it in to 7-12 and should be close enought (if you got this running)

 

the valave lash is mention if a tight valave or a lash pad fell out causing it to run on 3 cylinders or so.

But since you said it acted like it lost all ectrical power maybe the fuse in the ignition circut is loose at the ends inside. thuse breacking contack. replace the fuse. Was ignition light ON??????

 

I was hoping you took the rotor off also photo shop so to see the points but what I see it looks good. Rotor also looks correct as its in a BTDC fire order and the rotor goes CCW.

 

 

this is a simple fix.

 

 

to me the lash is too tight at .004 but cold it should start I would think.